import java.util.concurrent.Semaphore;

public class es6 {

	static Semaphore mutex = new Semaphore(1);

	public static void main(String[] args) throws InterruptedException {

		
		Print as = new Print("a");
		Print bs = new Print("b");
        mutex.acquire();
		as.start();
		
		
		mutex.acquire();
		bs.start();
		
	}

}
